Why can't I push a cloned repository with bitbucket?

Question

Bitbucket

Good afternoon.
I created an ssh key and added it to bitbucket, also on github.

Then I clone my repository, make changes, and try to push, and they write to me in response:

Unauthorized
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

I can't understand what is the problem?
I added the same key to github.
And everything works there.
Tell me, where did I mess up?
Thanks in advance.

Answer 1

Found a solution.
The fact is that bitbucket made it possible to add keys to repositories, although I don’t understand why this is needed?
This is where I got caught.
I added the key to the account and the problem disappeared.